﻿266 
  

  

  S. 
  Roth 
  — 
  Publications 
  of 
  Fl. 
  Ameghino. 
  

  

  In 
  the 
  " 
  Suplemento," 
  p. 
  12, 
  he 
  says 
  : 
  

  

  " 
  Polyacrodon 
  ligatus 
  Roth 
  p. 
  384, 
  corresponds 
  with 
  Dido- 
  

   loclus 
  multiciispis 
  Ameghino, 
  1897. 
  

  

  Megalacrodon 
  prolixus 
  Ruth 
  p. 
  384, 
  corresponds 
  with 
  Polya- 
  

   crodon 
  lanciformis, 
  Roth 
  p. 
  383, 
  and 
  Lamdaconus 
  suinus, 
  

   Amegh. 
  1897." 
  

  

  I 
  now 
  beg 
  to 
  compare 
  Fig. 
  1, 
  which 
  represents 
  Didolodus 
  

   midticuspis, 
  with 
  Fig. 
  2, 
  which 
  represents 
  the 
  upper 
  molar, 
  on 
  

   which 
  my 
  Polyacrodon 
  ligatus 
  is 
  founded. 
  While 
  the 
  latter 
  

   with 
  its 
  very 
  low 
  crown 
  in 
  the 
  form 
  of 
  cones 
  reminds 
  one 
  very 
  

   much 
  of 
  the 
  Marsupials, 
  the 
  former 
  shows 
  the 
  cones 
  in 
  Dido- 
  

   lodus 
  already 
  as 
  characteristic 
  features 
  of 
  the 
  Ungulates. 
  

  

  fi# 
  

  

  4a 
  

  

  Nevertheless 
  they 
  are 
  said 
  by 
  Ameghino 
  to 
  belong 
  not 
  only 
  to 
  

   the 
  same 
  genus, 
  but 
  to 
  the 
  same 
  species. 
  

  

  In 
  Fig. 
  3 
  1 
  have 
  reproduced 
  Lamdaconus 
  sui?ius, 
  and 
  in 
  

   Fig. 
  4<z 
  and 
  b 
  Megalacrodon 
  prolixus. 
  The 
  molars 
  of 
  the 
  lat- 
  

   ter 
  show 
  an 
  astonishing 
  likeness 
  to 
  those 
  of 
  Didelphys, 
  while 
  

   the 
  tooth 
  of 
  Lamdaconus 
  exhibits 
  clearly 
  the 
  shape 
  of 
  the 
  

   Patagonian 
  type 
  of 
  Ungulates. 
  These 
  two 
  animals 
  cannot 
  even 
  

   belong 
  in 
  the 
  same 
  family. 
  

  

  Any 
  further 
  discussion 
  seems 
  to 
  be 
  unnecessary. 
  

  

  